Prognostic parameters in recurrent colorectal cancer: A role of control or restaging by FDG-PET/CT

Abstract

Background/Aim. Colorectal cancer ranks the third most frequent cancer in the world. Approximately 40% of the disease recurs after surgical resection. Determination of predictive parameters for recurrence may help in stratification of patients and contribute to patient management. There are still very few studies which sought factors to predict the recurrence of colorectal cancer. The aim of this study was to examine the predefined risk factors in metastatic development and evaluate clinical significance of 18Ffluorodeoxyglucose (FDG) uptake. Methods. The study was conducted with 56 patients for whom FDG-PET/CT (FDG-positron emission tomography/computed tomography) was requested for the suspicious recurrence or metastasis by routine conventional screening tests. Thirty three patients in whom recurrence/metastases were established with final histopathologic diagnosis formed the malignant group, and 23 patients with no recurrence/metastases formed the benign group. Risk factors [age, serum carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (Ca 19-9) levels, the maximum standardized uptake volume (SUVmax), tumor size (TS), CT/magnetic resonance imaging (MRI) findings, sex, primary tumor localization, lymphovascular invasion, perineural invasion (PNI), initial neoadjuvant therapy, lymph node initial metastasis (ILNM) excision, stage, tumor differentiation] were compared between these groups. Results. CEA, Ca 19-9, SUVmax, TS, PNI, ILNM, FDG uptake pattern, pattern of lesions on CT and tumor differentiation were found statistically significant by univariate analysis. After multivariate analysis, SUVmax and ILNM remained as the main risk parameters impacting recurrence/metastases. Mean SUVmax was 7.25 in the benign group, while it was 11.7 in the malignant group (p = 0.019). ILNM was present in 66.5% of patients in the malignant group, and in 30.5% of patients in the benign group (p = 0.015). For an estimated cutoff value of 6.3 and 12.5, respectively on ROC curve, the calculated specificities were 61% and 87%, respectively. Conclusion. ILNM and SU-Vmax are the main risk factors for recurrence of colorectal cancer and the patients with these factors must be followed up carefully. FDG-PET/CT is very sensitive for the detection of recurrence/metastases of colorectal cancer and SU-Vmax appears to improve its specificity.

Diagnostic Performance of F-18 FDG PET/CT in the Detection of Recurrent Colorectal Cancer: Correlation with Biochemical Markers and Conventional Imaging Modalities

“…In addition, they recommend the use of FDG PET/CT in patients suspected of having recurrence not only with increased CEA levels but also regardless of CEA values [45]. According to Hancerliogullari et al, the main predicting risk factors for 59% of recurrence in CRC patients are SUVmax and initial nodal involvement, with AUC of 0.717 [95% CI: 0.581-0.854, p=0.006] [62].…”

Diagnostic Performance of F-18 FDG PET/CT in the Detection of Recurrent Colorectal Cancer: Correlation with Biochemical Markers and Conventional Imaging Modalities

“…Hancerliogullari et al evaluated several risk factors for recurrent CRC. The strong predicting factors for recurrence detected in 59% of patients were initial lymph node metastases and SUVmax values [ 65 ].…”

Exploring Potential Epigenetic Biomarkers for Colorectal Cancer Metastasis

“…Various imaging modalities are currently used in clinical practice to stage CRCs, each offering distinct strengths and limitations. Computed tomography (CT) scans can detect metastasis to the regional lymph nodes and other organs [23][24][25][26]. A contrast-enhanced CT scan is the standard imaging technique used for pre-operative local staging in colon cancer cases [27].…”

“…CT can also be combined with fluorodeoxyglucose positron emission tomography (FDG-PET) to detect otherwise occult metastases that conventional imaging methods might fail to detect [30,31]. The limitation of FDG-PET is that non-malignant conditions such as inflammation, fibrosis, and oedema can have increased FDG avidity, resulting in false positives [23]. Furthermore, FDG-PET may miss the detection of lesions smaller than 1 cm, and patients with mucinous CRC may yield false-negative results due to the low FDG uptake associated with the mucinous component [32][33][34].…”